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O2 SENSORS answered

Answering the question about O2 sensors, yes, in all cars they are very
important to the running of the car. They are not the most important sensor
though, the water temp one usually is. Anyway, the O2 sensor sniffs the
Oxygen content of the exhaust compared to the oxygen content outside the
exhaust. From that, and with the help of heat (600 degr. needed), the
chemical Zircrhomium (and others) emits an electrical charge, as the sensor
is grounded by the exhaust/engine. The computer puts out a reference voltage
of aprox.  .5 volts. This voltage is compared to the voltage coming out of
the sensor to determine the stoichiometric (sp?) ratio of the fuel/air
mixture. If the ratio is rich, say 13-1 (14.7-1 being ideal) the voltage
from the O2 sensor will higher than .5v and the computer will alter the
mixture. Vice/versa, 16-1 is lean and the poooter will richen the mixture.

If the sensor is deleted, or is bad, the computer will likely make up it's
own value, right around .5 volts, which if the engine is in a decent state
of tune, will run almost as well. To check a sensor, unplug the lead wire
(always black) and hook up to a simple volt meter. The engine exhaust must
be at least 600 Degr. F. The voltage should be jumping between .3 to .7
volts or there abouts. if it moves very slow or not at all, the sensor is
dead. You can also check the reference voltage from the pooter and it should
be between .4 and .6 and very steady. Hope that helps!!

                       Rolf Mair is: waves@epix.net
        Racing Resume for Sponsors/Corvettes for sale/Racing Pix @
    Head Coach and Founder of the Seventh Wave jr. Ski Racing Team @ Doe Mt.Pa
               1994,95,96 East Coast USA SCCA Solo 1 Champion